title: Evidence for uncharted biodiversity in the Albugo candida complex, with the description of a new species.
abstract: During the past two years the integrity of Albugo candida as the only species of Albugo parasitic to Brassicaceae has been challenged. The existence of two distinct species parasitic to Brassicaceae has been confirmed, to which a third species was added. For the purpose of further exploring the diversity of the A. candida complex, eight Albugo specimens on Draba lasiocarpa, D. nemorosa, and D. verna (Brassicaceae) were morphologically and molecularly compared with other Albugo species. Based on sequence comparisons and thorough investigation of the characteristics of the oospores, especially surface ornamentation, Albugo voglmayrii sp. nov., parasitic to Draba nemorosa, is described from five specimens collected in Korea and China. It differs from the previously described species, A. candida, A. koreana, and A. lepidii, by its oospore wall ornamentation. The morphological discrepancy is supported by high genetic distances to other species of Albugo in ITS rDNA and cox2 mtDNA. Albugo specimens from D. lasiocarpa and D. verna were grouped with A. candida, revealing that two distinct species may cause white blister rust on the genus Draba. Therefore, the paradigms that: (1) there is only a single species parasitic to Brassicaceae, that (2) oospore morphology is useful only for distinguishing between largely unrelated species; and (3) in general only one species of Albugo may occur on a single host genus need to be discarded.
authors.affiliation: Division of Environmental Science and Ecological Engineering, College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea.
authors.forename: Young-Joon
authors.initials: YJ
authors.lastname: Choi
authors.forename: Hyeon-Dong
authors.initials: HD
authors.lastname: Shin
authors.forename: Sebastian
authors.initials: S
authors.lastname: Ploch
authors.forename: Marco
authors.initials: M
authors.lastname: Thines
mesh_terms: D044822:Biodiversity; D019607:Brassicaceae / Q000382:microbiology*; D002681:China; D004271:DNA, Fungal / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D007723:Korea; D008969:Molecular Sequence Data; D009868:Oomycetes / Q000145:classification* / Q000166:cytology / Q000235:genetics / Q000302:isolation & purification*; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology*; D013172:Spores, Fungal / Q000166:cytology
chemical_list: D004271:DNA, Fungal; D004275:DNA, Ribosomal